The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
Free tracker included with every download this week
Is Drinking Coffee Good for Weight Loss?
Coffee may have a modest effect on weight management, but it's not a weight loss solution on its own. Caffeine can slightly boost metabolism and reduce appetite temporarily, but sustainable weight loss requires consistent dietary changes and physical activity. For UK adults looking for effective weight management support, prescription options like Mounjaro and Wegovy are available through NHS specialist services or private prescribing, alongside lifestyle changes. Our free BMI calculator and GLP-1 weight loss calculator can help you understand your starting point and explore what might work for you.
10,000+ calculations today · NHS-aligned thresholds · 100% free
Calculate Your BMI Instantly
Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
Coffee, Caffeine and Weight Loss: What the Evidence Shows
Caffeine does have some measurable effects on metabolism and appetite. Research suggests caffeine may increase metabolic rate by 3–11% temporarily and can reduce appetite in the short term, which might support a modest calorie deficit. However, these effects are small and vary significantly between individuals. Regular caffeine consumers also develop tolerance, meaning the appetite-suppressing effect diminishes over time.
For sustainable weight management in the UK, coffee alone is far too weak an intervention. You'd need consistent dietary changes, increased physical activity, and ideally professional support. That's where prescription weight loss medication comes in—GLP-1 weight loss injections like Mounjaro and Wegovy offer much stronger appetite regulation and have robust clinical evidence behind them. If you're interested in exploring medication options, our GLP-1 weight loss calculator can show you projected outcomes based on clinical trial data.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
UK Prescription Weight Loss Options: A More Effective Approach
If coffee and lifestyle changes alone aren't delivering results, prescription weight loss medication is available to eligible UK adults. The two most commonly prescribed options are Mounjaro (tirzepatide) and Wegovy (semaglutide)—both are once-weekly injections that work by regulating appetite and supporting feeling fuller on smaller meals.
Eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions like type 2 diabetes or high blood pressure. Access is available through NHS weight loss services (via GP referral to tier 3 specialist services) or private online prescribing. A licensed prescriber will assess whether medication is suitable for you. These medications are used alongside dietary and lifestyle changes—not instead of them.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
Does drinking more coffee help with weight loss?
Coffee may provide a very small metabolic boost and temporarily reduce appetite, but the effect is modest and diminishes with regular use. It's not a weight loss tool on its own. Sustainable weight loss requires a calorie deficit through diet and physical activity. For stronger support, prescription medication is available to eligible UK adults.
How much caffeine is safe to drink daily?
The NHS advises that most healthy adults can safely consume up to 400mg of caffeine per day—roughly 4 cups of instant coffee or 2–3 cups of filter coffee. Pregnant women should limit intake to 200mg daily. Individual tolerance varies, and caffeine can cause sleep disruption and anxiety in some people.
What prescription weight loss options are available on the NHS?
Mounjaro, Wegovy, and Saxenda are NHS-licensed for weight management. Access requires referral to a specialist tier 3 weight management service through your GP. Availability varies by region, and waiting times can be lengthy. Private prescribing is also available if you don't want to wait for NHS assessment.
How effective is Mounjaro compared to just changing diet and exercise?
Clinical trials showed Mounjaro helped participants lose an average of 15–21% of body weight alongside dietary changes and increased activity. This is significantly more than diet and exercise alone typically achieve. However, individual results vary, and medication is always combined with lifestyle changes, not used instead of them.
How do I find out if I'm eligible for prescription weight loss treatment?
Talk to your GP about your weight and health goals. You may be eligible if you have a BMI of 30 or above, or 27 or above with weight-related conditions. Your GP can refer you to a specialist service or discuss private options. Use our free BMI calculator to check your starting point before your appointment.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.